Preparative isolation and purification of xanthohumol from hops (Humulus lupulus L.) by high-speed counter-current chromatography.

Xanthohumol (XN) and related prenylflavonoids are the main bioactive components of hops (Humulus lupulus L.). The current work is to investigate the use of high-speed counter-current chromatography (HSCCC) in search for high isolation of xanthohumol from hops. A solvent system consisted of n-hexane-ethyl acetate-methanol-water at a volume ratio of 5:5:4:3 was employed. The results demonstrated that the constructed method could be well applied for the isolation of xanthohumol from hops extract. After HSCCC isolation procedure, the purity of xanthohumol was over 95% assayed by HPLC and the yield of extraction was 93.60%. The chemical structure identification of xanthohumol was carried out by UV, (1)H NMR and (13)C NMR. The present results demonstrated that xanthohumol could be efficiently obtained using a single HSCCC step from H. lupulus L. extract.

4-(4-Nitro-benzene-sulfonamido)pyridinium trichloro-acetate.

In the crystal structure of the title compound, C(11)H(10)N(3)O(4)S·C(2)Cl(3)O(2), the dihedral angle between the two six-membered rings is 69.2 (1)°. The mol-ecules are connected via inter-molecular N-H⋯O hydrogen bonding.

3,5-Dihydr-oxy-2-methyl-4H-pyran-4-one.

In the title compound, C(6)H(6)O(4), inter- and intra-molecular hydrogen bonds are observed which help to establish the crystal structure. There are weak π-π interactions between pyran rings separated by 3.5692 (9) Å.